import React, { Component } from 'react'
import './index.css'

export default class Footer extends Component {

  //全选checkbox
  handleCheckAll = (event) => {
    this.props.checkAllTodo(event.target.checked);
  }

  handleClearAllDone = () => {
    this.props.clearAllDone();
  }

  render() {
    const {todos} = this.props
    const doneCount = todos.reduce((prev,todo) =>  prev + (todo.done ? 1 : 0),0);
    const total = todos.length
    return (
      <div className="todo-footer">
        <label>
            <input type="checkbox" onChange={this.handleCheckAll} checked={doneCount === total && total !==0 ? true : false}/>
        </label>
        <span>
            <span>已完成{doneCount}</span> / 全部{total}
        </span>
        <button onClick={this.handleClearAllDone} className="btn btn-danger">清除已完成任务</button>
      </div>
    )
  }
}
